The general aim of these studies is to examine relationships between the kallikrein-kinin system and other blood pressure regulatory systems -- the arachidonate-prostaglandin, the renin-angiotensin-aldosterone, and the adrenergic nervous systems -- as affected by the balance of sodium and potassium, and to define the significance of such relationships to vascular and renal functions that contribute to set the level of arterial blood pressure. Firstly, we will utilize a variety of physiological, pharmacological, and biochemical techniques to investigate the functional consequences of stimulation of renal and pulmonary synthesis of prostaglandins by kinins in normal animals and in animals with electrolyte imbalance; possible differences will be related to modifications in the profile of prostaglandins products released by kinins from an organ. Secondly, we will perform studies to examine the influence of the kallikrein-kinin system on the vascular reactivity to angiotensins and to adrenergic stimuli. Thirdly, we will perform studies in the dog and in the isolated rat kidney to examine relationships between the kallikrein-kinin system and the secretion of renin. Finally, we will investigate the effect of alterations in the activity of the renin-angiotensin-aldosterone adrenergic nervous, and prostaglandin systems on urinary kallikrein and on levels of blood and urinary kinins.